package expr;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Created by gongxun on 2017/4/22.
 */
public class Token {
    public static final List<String> OPERATORS = Arrays.asList("+", "-", "*", "/");
    private static final Map<String,Integer> priorities = new HashMap<String,Integer>();
    static {
        priorities.put("+", 1);
        priorities.put("-", 1);
        priorities.put("*", 2);
        priorities.put("/", 2);
    }
    static final int OPERATOR = 1;
    static final int NUMBER = 2;
    String value;
    int type;
    public Token(int type, String value){
        this.type = type;
        this.value = value;
    }

    public boolean isNumber() {
        return type == NUMBER;
    }

    public boolean isOperator() {
        return type == OPERATOR;
    }

    public int getIntValue() {
        return Integer.valueOf(value).intValue();
    }
    public String toString(){
        return value;
    }

    public boolean hasHigherPriority(Token t){
        if(!this.isOperator() && !t.isOperator()){
            throw new RuntimeException("numbers can't compare priority");
        }
        return priorities.get(this.value) - priorities.get(t.value) > 0;
    }


}
